BeanComparator实现ArrayList中的元素按多个属性复合排序

import java.util.Collections;      
import java.util.Comparator;      
import java.util.ArrayList;      
import org.apache.commons.beanutils.BeanComparator;      
import org.apache.commons.collections.ComparatorUtils;      
import org.apache.commons.collections.comparators.ComparableComparator;      
import org.apache.commons.collections.comparators.ComparatorChain;      
 
public class CompareTipA  {      
    private int  id;      
    private String  name;      
    private String age;      
 
    @SuppressWarnings("unchecked")  
    public static void main(String []args) {      
 
        //在列表中加入若干CompareTipA对象  
        ArrayList<Object> list = new ArrayList<Object>();      
        list.add(new CompareTipA(1,"3","五"));      
        list.add(new CompareTipA(1,"1","六"));      
        list.add(new CompareTipA(1,"5","二"));      
        list.add(new CompareTipA(1,"4","四"));      
        list.add(new CompareTipA(4,"2","一"));      
 
        //创建一个排序规则  
        Comparator mycmp = ComparableComparator.getInstance();      
        mycmp = ComparatorUtils.nullLowComparator(mycmp);  //允许null         
        mycmp = ComparatorUtils.reversedComparator(mycmp); //逆序         
 
        //声明要排序的对象的属性，并指明所使用的排序规则，如果不指明，则用默认排序  
        ArrayList<Object> sortFields = new ArrayList<Object>();      
        sortFields.add(new BeanComparator("id", mycmp)); //id逆序  (主)      
        sortFields.add(new BeanComparator("name"));      //name正序 (副)   
 
        //创建一个排序链  
        ComparatorChain multiSort = new ComparatorChain(sortFields);   
 
        //开始真正的排序，按照先主，后副的规则  
        Collections.sort(list,multiSort);      
 
        for (int i =0;i<list.size();i++) {      
            System.out.println(list.get(i));    //输出      
        }      
        /** 
         * 输出结果如下: 
         * [id=4,name=2,age=一] 
         * [id=1,name=1,age=六] 
         * [id=1,name=3,age=五] 
         * [id=1,name=4,age=四] 
         * [id=1,name=5,age=二] 
         */ 
    }      
 
    public CompareTipA(int id, String name,String age) {      
        this.id = id;      
        this.name = name;      
        this.age = age;      
    }      
 
    public int getId() {      
        return this.id;      
    }      
 
    public void setId(int id) {      
        this.id = id;      
    }      
 
    public String getName() {      
        return this.name;      
    }      
 
    public void setName(String name) {      
        this.name = name;      
    }      
 
//    public int compareTo(Object o) {      
//        return this.comparator.compare(this, o);      
//    }      
 
    public String toString() {      
        return "[id=" + this.id + ",name=" + this.name +",age=" + this.age +"]";      
    }      
 
    public String getAge() {      
        return age;      
    }      
 
    public void setAge(String age) {      
        this.age = age;      
    }      
}